Collapsible weight handling boom



Sheet R. D- TESCH COLLAPSIBLE WEIGHT HANDLING BOOM Feb. 11, 1969 Filed Aug 28, 1967 H. C R5 m OE E &N mm +m m 0 I WW 1Q b0 1 4 Q lq fiilm N W WW \N a, lb JIN mm Q 7 O 0 Wm Feb. 11, 1969 R. D. TESCH 3,426,915

COLLAPSIBLE WEIGHT HANDLING BOOM Filed Aug. 28,1" 196? L I v J Pozsww? 15 E SCH BY 9 l, aq xzgwra -a I ATTQRNEYS United States Patent 3,426,915 COLLAPSIBLE WEIGHT HANDLING BOOM Robert D. Tesch, Washington, Ill., assignor to Caterpillar Tractor (30., Peoria, 111., a corporation of California Filed Aug. 28, 1967, Ser. No. 663,705 U.S. Cl. 212-8 Int. Cl. B66c 23/00, 23/62 Claims ABSTRACT OF THE DISCLOSURE It has long been known in the art that the use of weight handling booms facilitates the lifting and movement of large and heavy objects. However, one of the primary disadvantages of such weight handling booms is that in order to provide adequate lifting capabilities, the boom must be of a relatively long length. If the boom is to be mounted on a movable platform, such as a tractor mounted pipelayer, the boom must be removed from the vehicle if the vehicle is to be transported a great distance and if the boom is of such a length as to exceed road and tunnel height limits.

Although collapsible booms have been known in the art, those of prior inventions have been cumbersome in nature and expensive to manufacture and maintain.

It is therefore an object of this invention to provide a boom which may be collapsed against its platform so as to provide ease of transportation.

It is also an object of the present invention to provide a collapsible boom which may be collapsed about a hinge means intermediate the ends thereof by means of a force exerted by the load handling line of the boom.

It is also an object of the present invention to provide a weight handling means which is compact and easy to assemble and disassemble.

It is a further object of the present invention to provide a weight handling boom which may be mounted upon a transportable vehicle and collapsed thereagainst so as to provide a compact unit for transportation.

It is also an object of the instant invention to provide a weight handling boom wherein a means is provided on said boom for exerting a cantilever force against a portion of the boom so as to aid in the assembly and collapsing of the respective portions of the boom.

It is a further object of the invention to provide a weight handling boom which may be collapsed having a cantilever force exerting means thereon which itself may be collapsed against a portion of the boom for compactness.

Other objects of the invention will become apparent to those skilled in the art upon perusal of the following description of the preferred embodiments thereof as depicted in the drawings which are intended to illustrate but not to restrict the scope of the invention.

Referring now to the drawings:

FIG. 1 shows an end view of a vehicle carrying the load handling boom of the present invention assembled for load handling capability;

FIG. 2 shows an end view of a vehicle carrying the instant invention mounted in a partly collapsed position;

FIG. 3 is a view similar to FIG. 2 showing the load handling boom collapsed against the vehicle and the cantilever means in its extended position; and

FIG. 4 shows a partial plan view of the elements of the invention as viewed along a line IV-IV of FIG. 3.

Now referring to the drawings in greater detail, there is shown in the figures a vehicle 11 in the form of a tractor mounted pipelayer. Obviously the vehicle may be any similar vehicle or stationary platform without changing the detailed aspects of the invention. Mounted on the vehicle in cantilever fashion is a work handling boom 13 comprising a lower section 15 and upper section 17. The lower section 15 of the boom has on the upper end thereof a flange 19 which facially abuts a flange 21 mounted on the lower end of the upper section 17. When the boom is assembled, the flanges are joined as shown in FIG. 1 by means of a hinge pin 23 and flange bolts 25. The boom is pivoted on the vehicle by means of a pivot pin as at 27 and is supported and guided by suitable structure such as 28.

Mounted on the opposite side of the vehicle or platform so as to counterbalance any weight lifted by said boom are a plurality of hydraulically actuated counterweights 29 which, per se, comprise no portion of the instant invention.

Also mounted on the opposite side of the vehicle and between said counterweights is a two-drum winch 31 from which is operated a two part boom cable 33 and a load cable 35. The load cable, acting through a sheave 41, operates a tackle 37 having a load hook 39.

A cantilever member 42 carrying a sheave 53 is mounted on upper section 17 and is utilized in collapsing and assembling the boom. In order to perform this function, load cable 35 is slacked and cantilever member 42 is rotated counter-clockwise from that position shown in FIG. 1 to a position such that sheave 53 is below the cantilever pivot point 51. The cable is then trained over sheave 53 and re-tensioned, closing the blocks of tackle 37. The boom is then elevated to a vertical position by taking in boom cable 33 after which flange bolts 25 are then removed from the complementary flanges. Boom cable 33 is then taken in further and load cable 35 is played out so that the upper section 17 of the boom rotates about hinge pin 23 as shown in FIGS. 2 and 3. As can be seen from the drawings, the load cable 35 causes a cantilever force to be exerted on section 17 by member 42. Thus, the boom control cable 33 and the load, or work-handling, cable 35 cause moments of force or torque, to be exerted on section 17, forcing it to rotate about hinge pin 23.

Although cantilever member 42 is shown to be pivotable about pivot pin 51, it is obvious that if desired it may be fixed on upper section 17 and permanently held in the downwardly extending position shown in FIG. 3.

Load cable 35 may then be slacked, removed from sheave 53 and then re-tensioned to its storage position as shown in phantom in FIG. 3.

If desired, upper section 17 and lower section 15 may in fact comprise a plurality of parts, for example as shown in FIG. 4.

If such is the case, cantilever member 42 may comprise a main leg 43 and a support leg 45. Support leg 45 may be pivoted on the main leg as at 47 and removably attached to one of the upper portions as at 49.

If it is desired to mount the cantilever member 42 so that it is rotatable to the position shown in FIG. 1 thereby facilitating compactness in storage, support leg 45 may be pivoted against the member 43 and the entire cantilever member may thereafter be pivoted on pivot pin 51 to the position shown in phantom in FIG. 4.

Note that if such is desired the pivot pin may be mounted on the upper section 17 in such a manner that sheave 53, in the position of operation of the cantilever member as shown in FIGS. 2 and 3, is in the line of movement of load cable 35 but, in the storage position, is

offset from the line so as not to obstruct its passage, as shown in phantom in FIG. 4.

In order to raise the boom, the cantilever member, if pivotally mounted, is placed in the position shown in full lines in FIG. 4. The load cable 35 is slacked and trained over sheave 53 and then re-tensioned by winch 31. The operator then takes in load cable 35 while letting out boom cable 33. The force applied by cable 35 on cantilever member 42 rotates the upper section of the boom about hinge pin 23 in the manner shown in FIG. 2. There after, the parts are reassembled as shown in FIG. 1.

The present boom collapsing means is a true advancement in the art since the simplicity and ease of handling of the system is more useful in the art than other methods heretofore known.

What is claimed is:

1. In a collapsible weight handling boom comprising a lower section pivotally mounted at one end thereof on a support, an upper section pivotally mounted at one end thereof on the distal end of said lower section and releasable means prohibiting relative motion between said sections when fixed, said upper section having a workhandling mechanism at the distal end thereof, the improvement comprising a cantilever member mounted adjacent said one end of the upper section and having a sheave mounted on the distal end thereof, a work-handling cable extending from said support through said sheave to said work-handling mechanism and a boom elevation control means extending from said support to said distal end of the upper section whereby said work-handling cable and said boom elevation control means each apply a force moment to said upper section and thereby accurately control the erection or folding of said boom by rotating the upper section about its pivotal connection to said lower section when said releasable means are released.

2. The boom of claim 1 wherein said cantilever member is pivotally mounted on said upper section and movable from a first position for force application, as described, to a second position wherein it is folded against said upper section during use of said boom.

3. The boom of claim 1 wherein said sections each comprise a plurality of legs and said cantilever member comprises a plurality of legs each of which is mounted on one of the legs of said upper section.

4. The boom of claim 3, wherein the legs of said cantilever member are each pivotally mounted on one of the legs of said upper section.

5. The boom of claim 4 wherein one of the legs of said cantilever member is releasably pivoted to a first leg of said upper section and also pivotally attached to the other leg of said cantilever section whereby the cantilever member may be completely folded against a second leg of said upper section when not in use.

References Cited UNITED STATES PATENTS 2,336,965 12/1943 Shoemaker 2128 2,680,525 6/1954 Weatherby 212-144 2,682,957 7/1954 Holmes 212-8 3,073,457 1/ 1963 Thomas 212144 FOREIGN PATENTS 1,421,589 11/1965 France.

EVON C. BLUNK, Primary Examiner.

H. C. ,HORNSBY, Assistant Examiner.

US. Cl. X.R. 

